A comedy about girls joining the army in Denmark. Marianne joins to keep up a long family tradition as her brother won't. Both her brother and her boyfriend find her decision difficult to accept.

Hermann works at NATO headquarters in Brussels and is only home on weekends. He is quite a male chauvinist. That is why his wife Merete has not told him that she has pursued a career in the army and become a lieutenant. In Merete's regiment, Senior Sergeant Vasby suspects her of being a spy because of her "mysterious" conversations with NATO. This develops into an amusing spy hunt, and many people get involved. When Hermann is called up again, he "forgets" to tell his wife.

Women have joined the military in Denmark but may still not serve in the navy. This makes the lives of the sailors difficult when three women get trapped on board of a navy vessel do to an surprise exercise at sea. Trying to hide the three women leads to comical situations.